Chain-grate stoker



Fe'b. 21, 1928.

A. W. BENNIS CHAIN GRATE STOKER Filed Aug. 29. 1924 A 2 Sheets-Sheet l i M w .in. m m l 4 A Q 2 m. V// A 4 %x l /l Z u l&

Feb. 21, 192&

A. w. BENNIS CHAIN GRATE STOKER Filed Aug. 29. 1924 2 Sheets-Sheet 2 Patented Feb. 21, 1928.

; UNITED STATES Anrtnn WILLIAM BENms, or BOLTON, ENGLAND.

'oHAINenATE STOKER;

Applicationfiled August 29, 1924, Serial No.

The present invention relates to improvements in chain grates and the like stokers.

In order to prevent an undesirable leakage of air upwards into the furnace or leakage of products of combustion downwards at the sides of a grate adjacent to the furnace walls, various means have hitherto been suggested.

According to the present invention, a movable self-adjustingair seal plate, constructed preferably in parts, is employed at the sides of the grate. Each air seal plate rests on the top fiange of the side supporting frame of the grate, adjacent to the wall adjacent to the grate, and is capable of being automatically moved either towards the side of the grate or in an opposite direction if need be, by the action of a multiplicity of levers or the like acting themselves as springs, or in combination with springs or their equivalent, by which the air seal plate can be kept automatically pressed against the side of the grate. The levers may be in the form of leaf sprngs or in the form of rigid or semir elastic bars, combined with sprngs or ther equivalent, acting on them intermediate their length.

The present invention is more particularly described with reference to the accompanying drawings, in which Figurel is a sectional elevation of one form of Construction through an air seal plate and a side supporting frame of the grate. i

Fig. 2 is a diagrammatic partial side elevation of a chain grate with the inventions applied thereto.

Fig. 3 is a perspective View showing the relationship of a sealing bar, the furnace wall and the roller 11.

The side links 1 of a chain grate are engaged by a number of sealing bars 2 arranged in short sections along the grate, which have the sealing surfaces 3, 4:, fitting against the side walls of the links. These bars 2 are forced against the links 1 by the spring levers 5 whichare loosely mounted on the supports 6 at the base of 'the frame member 7 These spring levers 5 are drawn under tension toward the frame member 7 by the cap screws 9 which are threaded into them and pass through apertures'in the members 7 The coil springs 8 maintain this tension. The maximum inward movement 'of the *734,919, and in Great Britain March 11, 1924.

levers 5 is determined by the stop screws 20 in the frame 7 I At the upper ends, the levers 5 are bent inward into engagement with' the bars 2 which are thereby held in position.

At the side away from the links 1, the bars 2 have anges l() with downwardly inclined upper sui-faces and support the sealing rollers 11 which rest upon these surfaces and against the side wall of the ash-pit and thereby assist the seal.

In order to retard the flow of air upwards into the furnace, or the flow of gases down- 'wards from the furnace, around the edges of the grate, the sealing bars may each have a lip 13 projecting away from the. furnace proper beneath the supporting sill 14, so that the space between this sill, the wall of the ash-pit, and the bars 2 maybe wholly or partially filled with ash or other material, whereby a resistance is aftorded to the flow of gas or air through such materials between the bars and the furnace wall.

In operation, the spring ,levers 5 are held slightly fleXed by the pull of the springs 8 along the screws 9: the bars 2 are thereby' held in close engagement with the links 1. If a lateral movement of the links 1 occurs, or a wider portion of the grate comes past the bars 2, the latter are forced outward. This movement produces a further yielding of the spring levers 5, and of the coil springs 8. The head of screw 9 acts as a stop for the light spring 8, so that when an excessive movement occurs, the spring lever 5 in question is blocked, and acts only of its own elasticity.

I declare that what I claim is 1. A chain grate structure comprising a furnace frame, an endless chain of links supported on said frame, a plurality of independent sections constituting a sealing plate engaging the sides of said links, flanges formed on each of-said sections to receive a seal, sealing means located between said flanges and the wall of the furnace structure, and respective levers extending substantially the full depth of the frame and fulcrumed at the lower end o-n said frame and at their upper ends force the latter againstsaid links.

2. A sealing device for chain grates comprsing a sealing bar, a lever having elastieity in a plane at right angles to the links of said grate andadapted to press'said sealengaging said sealing plates to the walls of' lam of said lever toward the links Whereby to hold said bar in-elastic relaton With the sides of the links, a flange onsaid sealing bar With an outw ardly and downwardly inclned upf per surface, and a sealing roller supported by said surface and in contact With thewall of thefurnace structure;

In Witness Whereof, I have hereunto signed my name this 29th day'of July, 1924 ALFRED WVILLIAM BENNIS. 

